Abstract: In a disk drive, when an off-track error occurs during a sequential disk access operation that spans multiple contiguous data tracks, efficient recovery is performed. In an embodiment, the disk access operation (e.g., reading from or writing to a disk) is attempted for all sectors of the sequential disk access operation. The disk access operation is then attempted again for sectors associated with any off-track errors that occurred during the disk access operation. In another embodiment, when an off-track error occurs during a sequential write operation in a shingled magnetic recording drive, the data originally targeted to be written to a first portion is written to a second portion of the data track that follows the first portion. Since no additional revolutions of the disk are needed for data associated with the sequential write operation to be written to the disk.

Abstract: A motor according to the present disclosure is a motor including a motor body part and a driving circuit part, the motor body part including: a rotor; a stator including a wound coil; a winding terminal electrically connected to the coil and extending toward the driving circuit part; and a frame housing the rotor and the stator, wherein the driving circuit part includes: a case including a first attaching portion and a frame portion with openings on both end sides of the frame portion; a first wiring board including a driving circuit and a power device mounted on the first wiring board, the first wiring board being fixed to the first attaching portion; and a first electric wiring member including a first stress absorbing portion formed into a shape absorbing stress, the first electric wiring member electrically connecting the winding terminal and the first wiring board.

Abstract: According to one embodiment, a magnetic disk device includes a magnetic disk including a plurality of tracks, first and second actuators, and a control circuit. The magnetic disk includes the plurality of tracks. The control circuit writes, in a first track by using the first actuator, second data having a size corresponding to a first number among the first data. In addition, the control circuit writes, in a second track by using the second actuator, third data having a size corresponding to a second number among the first data. Each of the first track and the second track is a track among the plurality of tracks. The first number is a number of writable sectors included in the first track. The second number is a number of writable sectors included in the second track. The third data is data received subsequent to the second data.

Abstract: A disk drive according to an embodiment includes a disk, a first actuator having a first arm, a second actuator having a second arm, and a head. The head includes a write head and a read head. In addition, the disk drive includes a control unit calculating an amount of shift from an initial value of offset in a radial direction of the disk between the read head and the write head. The control unit controls the second actuator and corrects a position of the head to a position where the shift amount is reduced.

Abstract: A spatial light modulator (SLM) module and methods of designing, manufacturing and using the same are provided. In one embodiment, the SLM module comprises a diffractive, diffractive SLM formed on a substrate, the SLM including a plurality of pixels each including a plurality of electrostatically deflectable actuators, and a driver including a number of drive channels each coupled to one of the plurality of electrostatically deflectable actuators. Each of the drive channels include at least one internal digital-to-analog converter (DAC) integrally formed on the same substrate as the SLM. In one embodiment, the DAC is a multi-slope charge integrating DAC. In other embodiments, the driver includes circuitry to test each of the drive channels, and a spare drive channel that can be switched in to replace a defective drive channel.

Abstract: In a disk apparatus, media include first and second surfaces having first and second servo patterns which are read at different timings by first and second heads. A controller controls the first head based on a first demodulated position obtained by demodulating the first servo pattern and a target position. The controller calculates a first estimated demodulated position from the demodulated position and a first demodulated velocity based on the first servo patterns, calculates a second estimated demodulated position from the first demodulated position and a second demodulated velocity based on the second servo patterns, and stops writing operation of the first head in accordance with one of the first and second estimated demodulated positions exceeding a threshold.

Abstract: Systems and methods are provided for causing aural and/or visual presentation of representative content in response to a request to progress or navigate through audio content at a scan rate exceeding a threshold playback rate. In some embodiments, a current position marker in the audio content may be repeatedly updated based on the scan rate. For each updated position of the current position marker, one or more characteristic words associated with the content near the current position marker may be determined. A continuous presentation of the determined characteristic words may be generated and presented aurally and/or visually in order to provide an indication as to the subject matter of the content at the current position.

Abstract: A disk drive is disclosed comprising a disk comprising a plurality of tracks, and a head comprising a first read element and a second read element. A spacing of the first and second read elements is measured, and based on the measured spacing, the tracks are grouped into radial bands that define at least one one-dimensional recording area on the disk and at least one two-dimensional recording area on the disk. When the head is within a first two-dimensional recording area, data recorded on the disk is detected by processing a first read signal generated by the first read element and by processing a second read signal generated by the second read element using a two-dimensional demodulation algorithm. When the head is within a first one-dimensional recording area, data recorded on the disk is detected by processing the first read signal using a one-dimensional demodulation algorithm.

Abstract: Computer readable media, methods and apparatuses are disclosed that may be configured for sequentially reading data of a file stored on a storage medium. The disclosure also provides for alternating writing, in a sequential order, portions of the file data to a first buffer and a second buffer. The disclosure also provides for writing from a first buffer and a second buffer to a first track until the first track is filled.

Abstract: In a method for operating a tape storage system, readback signals are simultaneously received from a set of data readers reading from data tracks of a set of adjacent data tracks extending along a longitudinal extension of a tape storage medium, wherein each data track of the set has a width and each data reader of the set has a width equal to or less than the width of a data track. Simultaneously to receiving the readback signals from the set of data readers readback signals are received from a servo reader arrangement containing at least one servo reader arranged laterally offset from one of the data readers by less than the width of a data track. At least one of lateral position, velocity, gain and timing information is determined dependent on the readback signals of each servo reader in the servo reader arrangement.

Abstract: A method for operating a tape storage system includes simultaneously receiving readback signals from a set of data readers reading from data tracks of a set of adjacent data tracks extending along a longitudinal extension of a tape storage medium. Each data track has a width and each data reader has a width that exceeds the width of a data track. In the readback signal, of one of the data readers of the set a simultaneous presence of two defined waveforms is detected stemming from two different servo patterns arranged in servo sections of adjacent data tracks of the set. At least one of lateral position, velocity, gain and timing information is derived from a measure of the energy of the two defined waveforms detected in the readback signal of the data reader and applying this information in the operation of the tape storage system.

Abstract: An apparatus according to one embodiment includes a plurality of modules configured to at least read data stored on a magnetic recording tape, each of the modules having an array of readers. One module is configured to read data on a magnetic recording tape which none of the other modules can read. An apparatus according to another embodiment includes a first module configured to at least read data stored on a magnetic recording tape in a first range of formats, and at least a second module configured to at least read data stored on a magnetic recording tape in at least a second range of formats. The first range of formats does not include a format that is in the second range of formats. All of the modules are aligned along a tape travel direction.

Abstract: A system according to one embodiment includes at least two write transducers for writing to a magnetic medium; and a low reluctance path from a first pole of a first of the write transducers to a second pole of a second of the write transducers.

Abstract: An apparatus comprising a magnetic media and a read/write unit. The magnetic media may be configured to store data. The magnetic media may also be rotated during access of the magnetic media. The read/write unit may comprise a plurality of transducers arranged in a linear array. Each of the transducers may be fabricated on a semiconductor substrate with fixed head positions with respect to the magnetic media. The read/write unit may also be positioned in close proximity to and across the surface of the magnetic media. Each transducer may be configured to read data from the magnetic media and write data to the magnetic media.

Abstract: Computer readable media, methods and apparatuses are disclosed that may be configured for sequentially reading data of a file stored on a storage medium. The disclosure also provides for alternating transferring of fixed size portions of the file data to a first buffer and a second buffer, alternating processing of data blocks of the fixed sized portions in parallel from the first and second buffers by a plurality of processing threads, and outputting the processed data blocks.

Abstract: Example embodiments may provide a magnetic memory device. The example embodiment magnetic memory devices may include a plurality of memory tracks, bit lines, connectors, a first input portion, and/or selectors. The memory track(s) may be stacked on a substrate to form a multi-stack. A plurality of magnetic domains may be formed in the memory track so that a data bit may be represented by a magnetic domain and may be stored in an array. The bit line(s) may be formed along respective memory tracks. The connector(s) may form a magnetic tunnel junction (MTJ) cell with one data bit region of the memory track. The first input portion may be electrically connected to each memory track and may input a magnetic domain motion signal to move data stored on a data bit region of the memory track to an adjoining data bit region. The selector(s) may select a memory track from a plurality of memory tracks on which a reading and/or writing operation may to be performed.

Abstract: In one general embodiment, a recording system controller includes a controller controlling a timing of flux switching of adjacent pairs of writers such that the writers in a given pair do not switch substantially concurrently, and reducing a current of one of the writers in the pair while the adjacent writer is writing a transition. In another general embodiment, a recording system controller includes a controller controlling a timing of pulse writing of adjacent pairs of writers such that the writers in a given pair do not pulse substantially concurrently. In yet another general embodiment, a method includes controlling a timing of pulse writing or flux switching of adjacent pairs of writers such that the writers in a given pair do not pulse or switch substantially concurrently.

Abstract: A sequential information storage medium, comprising a plurality of servo patterns encoded lengthwise thereon, wherein each servo pattern encodes at least one LPOS bit and comprises a width less than 187 microns.

Abstract: The flying heights of magnetic heads of a disk drive are set using an FOD (flying on demand) method in a bank mode. A first signal for adjusting the flying height of a magnetic head is issued to each magnetic head and the value of the first signal is scaled by scale values set for the magnetic heads, respectively, with one of the scale values differing from the others. The value of the first signal is changed until the magnetic head associated with the scale value different from the others touches down. A flying height for the magnetic head which touched down is determined based on the value of the first signal at the time of touch-down. The process is repeated, however with a different bank of scale values each time and set in such a way as to cause the sequential touch-down of the remaining magnetic heads, and determinations of flying heights for the magnetic heads.

Abstract: A recording system controller according to one embodiment includes a controller capable of selecting a level of a current or voltage applied to a first writer during the creation of a magnetic transition based on a current in at least one nearby writer. A recording system controller according to another embodiment includes a controller capable of selecting a timing of a current change applied to a first writer based on a current in at least one nearby writer for compensating for an effect of crosstalk from the at least one nearby writer. A method according to yet another embodiment includes selecting a level of a current or voltage applied to a first writer or selecting a timing of a current change applied to the first writer based on a current in at least one nearby writer for compensating for an effect of crosstalk from the at least one nearby writer.

Abstract: Embodiments of the present invention help to improve the capacity and the performance of a disk drive device. According to one embodiment, a data track pitch is set to each recording surface. The recording surfaces are divided into bands. A hard disk drive (HDD) sequentially moves a head to an adjacent data track in a band and performs a head switch at the band end in its data accessing. On a recording surface, the number of data tracks in each band is variable; and each band is constituted by different number of data tracks as necessary. The number of data tracks in each band is set so that the radial position of the band end comes close to the radial position of the corresponding band end on another recording surface. Accordingly, even if the recording surfaces have different variation rates of the data track pitch in the radial direction, increase in process time due to head switches can be suppressed.

Abstract: A method for reading data from a magnetic recording tape having multiple adjacent data tracks according to one embodiment includes simultaneously detecting signals from a plurality of read devices, at least some of the read devices being positioned over multiple data tracks while other of the adjacent read devices are positioned over single data tracks; determining which of the read devices is positioned over a single data track; and simultaneously reading data from the data tracks using only those read devices over the single data tracks. A method for reading and writing data to a magnetic recording tape according to another embodiment includes simultaneously writing data tracks to a magnetic medium; and simultaneously reading the data tracks on the magnetic medium using a plurality of adjacent read devices; wherein the number of the adjacent read devices is at least twice the number of the adjacent write devices.

Abstract: A disk drive for implementing a head switch operation is disclosed. The disk drive comprises: an actuator; a first head and a second head attached to the actuator; a disk having a plurality of tracks; and a processor. The processor controls operations in the disk drive including: executing a head switch command from the first head to the second head; determining that a sync-up operation is not successful for the second head at a first track; applying a torque to the actuator to move the second head to a second track; and determining that the sync-up operation is successful.

Abstract: In one embodiment of a system and method for positioning a transducer head, the transducer head includes a first group of elements for reading data from or writing data to a set of tracks on a storage medium, and a second group of elements for reading data from or writing data to a set of tracks on a storage medium. A device supplies electrical power to the first group of elements to read data from or write data to a first position on the storage medium, and supplies electrical power to the second group of elements to read data from or write data to a second position on the storage medium different than the first position without coarse movement of the transducer head relative to the storage medium.

Abstract: A method of providing audio transmissions from an electronic device having internal audio multiplexing is disclosed. The method comprises combining a plurality of received audio input signals for output as a first mode of operation for the electronic device, where the electronic device is configured to output the plurality of audio input signals on at least one audio channel. When a priority audio signal is detected from one of the received audio input signals in the first mode of operation, the method interrupts playback of the remaining audio input signals with the priority audio signal as a second mode of operation for the electronic device and transfers, within the electronic device, the priority audio signal to the at least one audio channel once the priority audio signal is detected.

Abstract: A system and method for a servo controller (SC) used in an embedded disk controller for adjusting stored servo skew values based on measured skew values is provided. The system includes, a servo timing controller, wherein the servo timing controller includes a first register that stores measured servo skew values at a given time; a first set of registers that receive stored skew values and the measured skew values; and firmware that adjusts the skew values based on the measured skew values measured by a reference timer. The process includes, measuring actual skew values during a head change in a read operation; comparing the measured skew values with the stored skew values; adjusting the skew value based on the comparison; and adjusting a servo field timer based on the adjusted skew value.

Abstract: A system such as a tape head having multiple read devices, where the read devices have less than or equal to half the width of the write devices or data tracks. The read devices are aligned adjacent to one another in the track width direction. Data tracks and guide bands can be used for track following, while a preferred embodiment uses additional readers to read servo bands for track following purposes.

Abstract: A magnetic recording disk drive has disks with identical pre-patterned servo patterns on their front and back surfaces and a servo control system for positioning the read/write heads using the servo signals from the identical servo patterns. The servo sectors on the two disk surfaces form identical patterns of angularly spaced arcuate-shaped lines that extend generally radially across the data tracks. The arcuate-shaped lines on one surface, the front surface, generally replicate the path of the recording head as it is moved across the data tracks by a rotary actuator, so that there is a constant sampling rate of the servo sectors on the front surface regardless of radial position of the head. However, the arcuate-shaped lines on the other surface, the back surface, do not replicate the path of the recording head so the servo sampling rate is not constant but varies with radial position of the head.

Abstract: Embodiments of the invention provide a data storage device and its control method that are capable of minimizing the possibility of head deterioration while maintaining the minimum required sustained data rate. In one embodiment, each track is divided into three areas (A, B, and C). When a ? track is accessed, the head is changed to access a ? track on the next recording surface. In this instance, LBAs are assigned to disks so that heads Hd0 through Hd4, which access both surfaces of disks 0 and 1, are selected for accessing purposes in the Hd0, Hd1, Hd2, Hd3, Hd0, and Hd1 order while an area selection is made in the area A, area B, and area C order.

Abstract: A magnetic disk drive includes an actuator arm, a suspension fixed to a tip end of the actuator arm, and a head slider having at least two electromagnetic transducers mounted at a tip end of the suspension. The head slider has a first electromagnetic transducer inclined in a direction in which the inner side face side is nearer to an air outflow end than a central portion thereof, and a second electromagnetic transducer inclined in a direction in which the outer side face side is nearer to the air outflow side than the central portion thereof. A controller performs changeover control such that an inner side data region of a magnetic disk is taken charge of by the first electromagnetic transducer while an outer side data region is taken charge of by the second electromagnetic transducer.

Abstract: A disk storage device has a plurality of disk faces and a plurality of heads. The disk storage device protects the data on the disk face for a head before the defect of the head occurs. For each head, a table for accumulating the error generation count generated by the operation of a head is provided. And a control unit predicts the defect of one head based on the accumulated error generation count, reads data on the corresponding disk face by the head of which the defect was predicted, and writes the read data to another corresponding disk face by another head. Since the defect of a head can be predicted, the data can be protected in advance.

Abstract: A set of coils wind around a magnetic core in a thin film magnetic head. Current supplying circuits are separately connected to the individual coils. The individual coils get shorter in the overall length as compared with the case where a set of coils consist of a single conductor. The impedance of the coils can be reduced. The reduction in the impedance enables the flow of the electric current to be established in a moment within the coils. The magnetic field of a sufficient intensity can be generated in a moment. Magnetization of a sufficient intensity can thus be established on a magnetic recording medium even when the frequency of a signal for recordation gets higher.

Abstract: A conventional magnetic head has a structure, in which a MR element and a recording element are stacked. The influence of a recording magnetic field on the magnetically sensitive portion of a reproduction element is lessened and the performance of the MR element is stabilized. Also, the reliability of the magnetic disk drive using a MR element is enhanced. The magnetic disk drive uses a composite magnet head, which has a plurality of reproduction elements arranged such that the magnetically sensitive layer of a reproduction element of the composite magnetic head does not overlap with the normal direction projection of the recording element, and which lessens the influence of a recording magnetic field on the magnetically sensitive portion of each reproduction element.

Abstract: A plurality of recording media combined integrally having a plurality of recording surfaces; and a plurality sets of reading heads and writing heads, combined integrally, provided for the respective ones of the plurality of recording surfaces, are provided. Upon writing data on each recording medium with the writing head provided therefor, a writing position is controlled as a result of positioning information previously provided on the recording media including the recording medium other than the each recording medium being read with the reading heads provided therefor.

Abstract: A method and system of switching heads in a hard disk drive written using an off-line STW method. In the method, first, deviations between a reference head and each of the heads are calculated. Next, a mapping table having the deviations between the reference head and each of the heads is generated and stored in a memory. Thereafter, when a head switching operation is requested, a current head is switched to a new head to access a track whose number is the same as the track assessed by the current head. A deviation of a track on which the head is positioned, recorded in the mapping table, is applied to the virtual track address of the track on which the head is positioned, thereby obtaining the physical track address of the track on which the head is positioned. The requested track is then accessed based on the obtained physical track address.

Abstract: A self-Redundant Array of Inexpensive Disks (RAID) system using a hard disk drive having a backup head and a method of writing data to and reading data from the hard disk drive having the backup head are provided. A self-RAID (Redundant Array of Inexpensive Disks) system using a hard disk drive with at least one writable and readable disk medium includes a spindle motor, heads, an actuator arm, and a controller. The spindle motor rotates the disk medium. The heads face each other above and below the disk medium. The actuator arm drives the heads. The controller controls the heads to write data to and read data from the disk medium using a mode selection signal.

Abstract: In a disk device in which heads are positioned by a servo mechanism, the object of the present invention is to prevent data from being destroyed by incorrect selection of a head and to improve reliability in recording or reproducing information and to prevent format efficiency from being decreased thereby. For this object, a SAM pattern in a servo information region is changed for each head and recorded. Then, the SAM pattern is read to determine which head makes access to a disk surface and the head is compared with a head to which a direction of making access is given thereby to make an error check. Moreover, by the use of a marker pattern of rotational synchronization compensating data added to the servo information, an error check of the head making access to the disc surface is conducted.

Abstract: A recording system of a magnetic tape drive is operated to cause one separate set of write heads to write data discontinuously to magnetic tape as received, and to save the data, and, during the same operation, to cause another separate set of write heads to rewrite data to magnetic tape in a continuous arrangement. The writing may be in parallel and simultaneous. Thus, during the same operation, and at the same time, the separate sets of the plurality of write heads, temporarily write the received data to magnetic tape so that the sender can erase its copy, and rewrite the saved data to the magnetic tape in a permanent arrangement, without waiting to complete first writing received data, to complete subsequently rewriting the data, and repeating.

Abstract: A disk device that has displacement of servo signals in the circumference direction and radius direction between a plurality of disks, prevents a drop in performance due to the displacement when the heads are switched. To deal with the displacement in the circumference direction, the sector numbers on the disk are converted by a table for each head. Also the servo gate time is corrected by the table according to the eccentricity of the disk, so the servo signal detection accuracy improves. Also to deal with the displacement in the radius direction, the track numbers on the disk are converted by the table using the difference value based on the reference head.

Abstract: A recording target error rate is selected for one or more of data storage devices, and for each data storage device, a dither value is determined for each read/write head in the data storage device, wherein for each head, using a dither value for writing data, essentially provides the selected recording target error for all the heads.

Abstract: A recording/reproducing apparatus capable of switching over among a plurality of heads with high precision, wherein the apparatus is provided with: a recording/reproducing unit for recording/reproducing signals onto/from a recording medium with a plurality of heads; a generating unit for generating control data for controlling the recording/reproducing unit; and a transmitting unit for transmitting control data generated by the generating unit to the recording/reproducing unit, wherein priority is given in transmission to data for controlling the switching of the plurality of heads over other data.

Abstract: A disc drive has transducers supported by an actuator to fly proximate data tracks on surfaces of rotating information storage discs. Each of the discs is partitioned into concentric regions. A control system arranges the deposition of data in write operations to the tracks on the disc surfaces, as data is written to the discs, such that the data is sequentially organized both on the tracks and within each of the regions. The control system writes data from a track adjacent a first region boundary in a first direction to a second region boundary until all tracks in a region are full. The control system executes a head switch between adjacent surfaces of the discs. The write sequence is repeated in each adjacent region until all regions are full. The resulting trapezoidal serpentine pattern of actuator movement and head switches is repeated until all of the write operations are complete.

Abstract: A recording system of a magnetic tape drive is operated to cause one separate set of write heads to write data discontinuously to magnetic tape as received, and to save the data, and, during the same operation, to cause another separate set of write heads to rewrite data to magnetic tape in a continuous arrangement. The writing may be in parallel and simultaneous. Thus, during the same operation, and at the same time, the separate sets of the plurality of write heads, temporarily write the received data to magnetic tape so that the sender can erase its copy, and rewrite the saved data to the magnetic tape in a permanent arrangement, without waiting to complete first writing received data, to complete subsequently rewriting the data, and repeating.

Abstract: For the purpose of providing technique by which even when large skew of a disk or a head occurs due to a thermal shock, an outside shock, or the like, a servo signal area is not extended, and a performance loss caused by head change is not produced, a servo detection control system according to the present invention comprises: a learning means by head change including a servo sector interval measuring unit for measuring an interval of servo signal areas, which may occur at the time of head change among a plurality of heads; a time difference calculating unit for calculating head-change time difference from a value measured by the servo sector interval measuring unit; and a time difference storage unit for storing a result of calculation made by the time difference calculating unit; and a compensation and control means for compensating start timing of servo detection after head change using a stored value of the time difference storage unit.

Abstract: The present invention relates to repeatable runout (RRO) compensation of servo control systems that can be used in disc drives or spin-stands. The RRO relates to eccentricity between servo tracks, which were written onto a disc prior to the installation of the disc into the disc drive or spin-stand, and an axis of rotation of the disc. The present invention compensates the servo control loop by canceling the RRO and controlling a head to follow virtual tracks which are eccentric to the data tracks defined by the servo tracks and concentric with the axis of rotation of the disc.

Abstract: In a head positioning method and device in which the position of servo signals between heads is not uniform, it is aimed to reduce the time taken to find the servo signals when heads are switched. A storage disk device comprises storage disks with the servo signals, a plurality of heads that read the information from the storage disks, an actuator that moves the heads, and a control circuit that positions the heads based on the servo signals read from the storage disks by a selected head. This control circuit includes a synchronization circuit that, in response to a head switching cue, synchronizes the time of a servo gate signal (of the head to which switching is directed) for detecting a servo signal with the time of the servo signal read by the head to which switching is directed, and a processing circuit that reads the servo signal for the head in response to the synchronized detection signal and positions the head in response to the servo signal read.

Abstract: The present invention decreases the number of repositions during read back by making use of multiple read elements associated with each data track. A tape system includes a tape head with two read elements associated with each data track to be simultaneously read. Each read element generates a read signal in response to information recorded on the data track. Read electronics convert the read signal into read data. Control logic selects one of the two read elements as a source for output data for each data track. In response to a read error, output data is obtained from the other of the two read elements.

Abstract: An apparatus and method for dynamic head switch timing recalibration are provided. With the apparatus and method, a determination is made as to whether a difference in a reference head switch timing and the head switch timing at a later time is sufficient to meet a certain criteria. If the difference meets the criteria, a recalibration of the head switch timing is performed. For example, in a preferred embodiment, the criteria is a number of address mark (AM) misses during a head switch operation. If this predetermined number of AM misses is detected, then it is determined that a recalibration is necessary since the predetermined number of AM misses is an indication that the head switch timing has changed significantly from the reference head switch timing.

Abstract: The present invention decreases the number of repositions during read back by making use of multiple read elements associated with each data track. Each of a plurality of sets of read electronics receives the read signal from either one or the other of the two read elements associated with each data track and converts the received read signal into read data. For each data track, control logic selects one of the two read elements as a source for output data. In response to a determination that a read error has occurred, the control logic selects the other of the two read elements as the source for output data. For each data track, one read element is offset relative to the other read element in an offset direction normal to the tape direction.

Abstract: A modified disk drive that includes means for selectively and permanently disabling the write mode of the hard disk drive by the use of programmable read only memory (PROM) circuitry is provided. One method of use employs selectively blowing a PROM fuse in the arm electronics of the hard disk drive to prevent further writing to a respective disk surface in the hard disk drive. A second method of use employs selectively blowing a PROM fuse in processor-accessible memory, to prevent further writing to a section of logical block addresses (LBAs) corresponding to a respective set of data sectors in the hard disk drive.